The COG SDC consists of experienced Ph.D. level statisticians located at major universities directing the statistical analysis of COG data. In addition to this strong core of professionals, COG data are collected, managed and archived at one location: the COG Research Data Center at the University of Florida in Gainesville FL. This model combines the experience of professional statisticians, some of who have worked in pediatric oncology for more than 20 years, with a data management center with a long history of service to the pediatric research community. This model provides significant advantages to the research agenda of COG. The statistical leadership is comprised of individuals with significant experience in the design and analysis of clinical trials. Data are collected at a single site using uniform conventions and overseen by individuals with years of experience in this area. This makes data collection more efficient for institutional investigators and promotes the aggregation of large databases representing years of clinical trials work. The major goals of the SDC are: (1) participate in setting Group scientific priorities in specific disease areas through membership on strategy groups, tasks forces, and discipline committees; (2) evaluate COG therapeutic, epidemiologic, and biologic studies that are proposed or in development, to ensure the stated study aims can be accomplished (3) provide a study design, data acquisition plan and study analysis plan that ensures the study aims will be addressed correctly and efficiently, with appropriate monitoring of patient safety. (4) Perform statistical analyses of data relevant to interim monitoring and final reporting of the results of COG studies; (5) ensure that the needs of COG studies for data collection, computerization, report generation, committee review, safety monitoring, data quality control and institutional performance are met; (6) Investigate and test current information technology tools and adopt those that provide the most efficient means of quality data collection; (7) Establish policies for study conduct that ensure appropriate evaluation of study questions; (8) develop or extend statistical methodology to address unique problems arising in Group investigations; and (9) Provide training in the statistical aspects of the Group's scientific endeavors to various members of COG.